biglar155
Jetboaters Admiral
- Messages
- 1,577
- Reaction score
- 2,142
- Points
- 277
- Location
- Fredonia, WI
- Boat Make
- Yamaha
- Year
- 2009
- Boat Model
- SX
- Boat Length
- 23
I started to put this in "show us what you see" but it turned into a book so I'll post it over here instead. 
Here's what I saw yesterday:
My wife's reaction to seeing her most important tool in such a state:
So here's the story: The heating element on our oven went out about a month ago. Changing it was simple enough, but when I did so, I saw that the bottom of the oven had warped and steel had actually cracked. The replacement part came in last week and this is how far apart I had to tear things in order to install it.
On top of this, the thing started having another issue: Overheating. Twice in a three-month span the thing went over-temp on us. After the first incident, I ordered a new temperature probe. The second overtemp incident occurred last week on the same day the new bottom showed up. We stopped using the oven completely at that point.
(Now, I have to digress for just a moment. Those who know me know of my love for Thanksgiving It is my favorite Holiday. Tradition is a big deal to me and the fantastic turkey dinner that my wife prepares for us is second to none. With an oven starting to act a bit "janky" I've been growing ever more concerned about the possibility of a Turkey Dinner gone awry due to an equipment failure. Every morning I've glanced at the calendar and done the mental math to calculate when we'd have to place an order to make sure we had a new oven here by Thanksgiving Day. This weekend was do-or-die time.)
The mess pictured above was rock-bottom of the tear down. It actually did go back together fairly smooth. You just have to mind a lot of sharp sheet-metal edges and keep track of where every screw went. (There were a lot.)
During disassembly, I found the technicians guide and instructions to put the oven into test mode. This allowed me to test each relay as well as get a direct reading from the oven temperature probe. This would come in handy later.
After replacing the oven bottom and then the temperature probe, I fired it up to 400 Deg. Mozzarella sticks were baked without a problem. Still suspicious, I sat next to the oven with a flashlight watching the oven thermometer I had hung on the rack inside.
After about 30 minutes of waiting, I got what I was hoping to see: It was overheating again.
Now that I knew hot to put the system in test mode, I immediately did so. The temperature probe was reading the same high temperature I saw on the thermometer. This meant that the oven KNEW it was over temp, it just wasn't turning the burner off.
Then I hit the button to test the relay for the bake element. The normally loud "click" didn't happen. I tapped the button a few more times and was treated to the mushy sound of a relay with stuck contacts (25 years of industrial automation teaches you that sound).
I powered it down, unplugged it, and pulled out the control board. A quick look at repairclinic.com revealed the price of a new control board: $260. Ugh.
But wait.... The Broil relay and the Bake relay are the same part number. She never uses the Broil function.
So about 30 minutes later I had de-soldered both relays and re-soldered the Broil relay into the Bake relay location.
Everything went back together and she's been working perfectly ever since.
I jumped on Newark.com and ordered two replacement relays. Total cost is $11 and some change. The shipping was almost $6.
I'll change both relays after Thanksgiving so as not to cause any unnecessary down-time.
So here's my theory of what happened:
The relay must have been sticking closed intermittently for a long time. I noted that "normally" even when the oven is pre-heating it cycles the bake element on-and-off. This is probably to keep the temperature rise at a controlled rate and allow them to use thinner, cheaper material in the oven's construction.
With the relay sticking only occasionally, it likely caused localized overheating at the oven-bottom multiple times. The overheating led to the bottom of the oven warping and cracking. This would also lead to premature failure of the burner element itself.
An Autopsy of the failed relay revealed that the contacts were pretty gummed up:
(I had done a little bending and flexing to inspect at this point. That piece on the right is normally vertical. You can see the "smokyness" on the inside of the case.)
So, in the end, I don't think I needed a new temperature probe, but I do think I'm going to have to put those relays on a 3 year replacement PM schedule.
We can't have an equipment failure interfering with my stomach!
Here's what I saw yesterday:
My wife's reaction to seeing her most important tool in such a state:
So here's the story: The heating element on our oven went out about a month ago. Changing it was simple enough, but when I did so, I saw that the bottom of the oven had warped and steel had actually cracked. The replacement part came in last week and this is how far apart I had to tear things in order to install it.
On top of this, the thing started having another issue: Overheating. Twice in a three-month span the thing went over-temp on us. After the first incident, I ordered a new temperature probe. The second overtemp incident occurred last week on the same day the new bottom showed up. We stopped using the oven completely at that point.
(Now, I have to digress for just a moment. Those who know me know of my love for Thanksgiving It is my favorite Holiday. Tradition is a big deal to me and the fantastic turkey dinner that my wife prepares for us is second to none. With an oven starting to act a bit "janky" I've been growing ever more concerned about the possibility of a Turkey Dinner gone awry due to an equipment failure. Every morning I've glanced at the calendar and done the mental math to calculate when we'd have to place an order to make sure we had a new oven here by Thanksgiving Day. This weekend was do-or-die time.)
The mess pictured above was rock-bottom of the tear down. It actually did go back together fairly smooth. You just have to mind a lot of sharp sheet-metal edges and keep track of where every screw went. (There were a lot.)
During disassembly, I found the technicians guide and instructions to put the oven into test mode. This allowed me to test each relay as well as get a direct reading from the oven temperature probe. This would come in handy later.
After replacing the oven bottom and then the temperature probe, I fired it up to 400 Deg. Mozzarella sticks were baked without a problem. Still suspicious, I sat next to the oven with a flashlight watching the oven thermometer I had hung on the rack inside.
After about 30 minutes of waiting, I got what I was hoping to see: It was overheating again.
Now that I knew hot to put the system in test mode, I immediately did so. The temperature probe was reading the same high temperature I saw on the thermometer. This meant that the oven KNEW it was over temp, it just wasn't turning the burner off.
Then I hit the button to test the relay for the bake element. The normally loud "click" didn't happen. I tapped the button a few more times and was treated to the mushy sound of a relay with stuck contacts (25 years of industrial automation teaches you that sound).
I powered it down, unplugged it, and pulled out the control board. A quick look at repairclinic.com revealed the price of a new control board: $260. Ugh.
But wait.... The Broil relay and the Bake relay are the same part number. She never uses the Broil function.
So about 30 minutes later I had de-soldered both relays and re-soldered the Broil relay into the Bake relay location.
Everything went back together and she's been working perfectly ever since.
I jumped on Newark.com and ordered two replacement relays. Total cost is $11 and some change. The shipping was almost $6.
I'll change both relays after Thanksgiving so as not to cause any unnecessary down-time.
So here's my theory of what happened:
The relay must have been sticking closed intermittently for a long time. I noted that "normally" even when the oven is pre-heating it cycles the bake element on-and-off. This is probably to keep the temperature rise at a controlled rate and allow them to use thinner, cheaper material in the oven's construction.
With the relay sticking only occasionally, it likely caused localized overheating at the oven-bottom multiple times. The overheating led to the bottom of the oven warping and cracking. This would also lead to premature failure of the burner element itself.
An Autopsy of the failed relay revealed that the contacts were pretty gummed up:
(I had done a little bending and flexing to inspect at this point. That piece on the right is normally vertical. You can see the "smokyness" on the inside of the case.)
So, in the end, I don't think I needed a new temperature probe, but I do think I'm going to have to put those relays on a 3 year replacement PM schedule.
We can't have an equipment failure interfering with my stomach!
)
